(NSFW) What would you do, if your partner or yourself could not have intimate relations?

This is more aimed toward people in a longer term relationship. What would you do if either of you became unable to have intercourse for an unspecified period. This could be due to illness or other. Would you find other ways to satisfy sexual needs together excluding intercourse? How would this be for you? Does sex have to include full intercourse to be classified as sex? Or can other types of closeness aside from penetration be just as satisfying?

Would you be afraid that your partner would stray if it were you for example that could not have full intercourse?