I’m a heterosexual human male. Is it wrong to kiss a female mouth to mouth? Or on the neck? Even with her consent?
The 5th precept refers to sex (including oral).
The main thing is you need the parent’s or protector’s permission (at any age), before doing those level items.
There are also laws involved as well. For instance if she is too young to consent, you could get in trouble for doing “minor acts”. It would be bad to do as well.
There are also problems with doing “minor acts” to religiously protected people.
Even further, the Buddha said, that if you are old enough for gray hair and she is young, it is a cause for downfall.
Thera are also problems of “taken (married) women” who are sort of “protected” but kissing would be a problem too.
In short you have to look at the literal rule and follow that as a main guide. In addition, you should use your best judgement, Does this get anyone upset and angry or are there laws being broken?
Celibacy is the best course of action.
Even better is to join the monastic order to support that decision.