Coitus reservatus (from coitus, "sexual intercourse" and reservatus, "reserved"), also known as sexual continence, is a form of sexual intercourse in which a male does not attempt to ejaculate within his partner, avoiding the seminal emission. It is distinct from death-grip syndrome, wherein a male has no volition in his emissionless state.

Alice Stockham coined the term karezza, derived from the Italian word carezza meaning "caress", to describe coitus reservatus, but the idea was already in practice at the Oneida Community. Alan Watts erroneously believed that karezza was a Persian word. The concept of karezza is loosely akin to maithuna in Hindu Tantra and sahaja in Hindu Yoga.

Ejaculation control was important for both genders, in Chinese it is called caiyin buyang (traditional Chinese: 採陰補陽; simplified Chinese: 采阴补阳; pinyin: Cǎi yīn bǔ yáng; lit. 'collect yin and replenish yang') for men and caiyang buyin (traditional Chinese: 採陽補陰; simplified Chinese: 采阳补阴; pinyin: Cǎi yáng bǔ yīn; lit. 'collect yang and replenish yin') for women, and was involved in Taoist sexual practices such as huanjing bunao (traditional Chinese: 還精補腦; simplified Chinese: 还精补脑; pinyin: Huán jīng bǔ nǎo), as well as Indian Tantra (where it is known as "asidhārāvrata") and Hatha Yoga (see vajroli mudra), although conventional ejaculation is also endorsed.

Stockham writes, "Karezza signifies 'to express affection in both words and action', and while it fittingly denotes the union that is the outcome of deepest human affection, love's consummation, it is used technically throughout this work to designate a controlled sexual union." So that, in practice, according to Stockham, it is more than just self-control, but mutual control where the penetrative partner helps the receptive partner and vice versa. According to Stockham, this is the key to overcoming many difficulties in controlling sexual expression individually.

Stockham's contribution was to apply this same philosophy of orgasm control to women as much as to men. A form of birth control, the technique also prolongs sexual pleasure to the point of achieving mystical ecstasy. In this practice, orgasm is separated from ejaculation, making possible enjoyment of the pleasure of sexual intercourse without experiencing seminal ejaculation, while still experiencing orgasm.^{[citation needed]}

Some would have the principles of karezza applied to masturbation, whereby a person attempts to delay orgasm as long as possible to prolong pleasure in a process known as "orgasmic brinkmanship", "surfing", or "edging", but this is different from the practice of "karezza" in partnered intercourse. In Latin literature, this is known as coitus sine ejaculatione seminis.

One purpose of karezza is the maintenance and intensification of desire and enjoyment of sexual pleasure within relationships. ^{[citation needed]} According to Stockham, it takes from two weeks to a month for the body to recover from ejaculation: "Unless procreation is desired, let the final propagative orgasm be entirely avoided". Stockham advocated that the 'honeymoon period' of a relationship could be maintained in perpetuity by limiting the frequency of ejaculations, or, preferably avoiding them entirely.

Kalman Andras Oszlar writes, "Inasmuch as sexual togetherness is not limited into the physical world and does not mean quick wasting of sexual energies, by this we give free way to higher dimensions in the relationship." Affected by this, we may get into the state of flow, and in the course of this, the couple charges up with energy, while – with focused attention (Dhāraṇā) – the couple is submerging in that in which they are having pleasure. This state of mind is connected with the beneficial effects of tantric restraint and transformation. At first, Mihály Csíkszentmihályi defined positive philosophy, and since then, it has been referred to beyond the professional line. According to the professor, the flow experience is an entirely focused and motivationally intensified experience where people can entirely focus and properly command their feelings for the best performance or learning.