I'm trying to discipline myself to avoid just commenting on other comments. It forces me to take the question itself as a starting point. So a general comment only: Only a few of the comments address the non-verbal, and the relationship between verbal and non-verbal, which is a subject of special interest for theatre.

Yes/no are verbal. They have "quotes" around them - unless by using quotes you're hinting that they're not "just words." In any event, they may be necessary, but they are not sufficient. Our law and common sense both consider diminished capacity. Drunk/drugged/under-age persons are not capable of consenting, even if they say "yes," enthusiastically or otherwise.

Speaking of enthusiasm. By introducing this word, and introducing it first (good work!), the question specifically if subtly prompts us to consider the non-verbal. And it suggests that the non-verbal comes first. When you approach someone, what intent guides your action? When you respond to an approach, what intent guides your action? (By non-verbal, I'll include our own interior monologues -- verbal, but not expressed to the other person.)

Taking a hint from the order of words in the question... one might ask first: "Do I practice the enthusiastic in my encounters?" Or do I practice the compulsive, the habitual, the manipulative...? Some honest self-examination never hurt anyone.

Not to nitpick, but "enthusiasm" is derived from the idea that actions are motivated from outside the body -- divine possession. There are two belief systems here. One is the belief that actions flow ultimately and/or only from some non-material origin -- the spirit. This kind of spirit-motivation gets lip service, but I'm not sure we really believe it. The other belief is that actions flow only from a material origin -- a bodily origin. That is, my actions flow from my own materiality. That doesn't mean they flow only from my own individual materiality. We are a species. I may make my actions and my intents, but I did not make my contexts. What I have to work with here is in significant part inherited, evolved, discovered.