I have listed myself as “heteroflexible” in my profile. I would consider with the right guy, the following:
Masturbation - mutual self masturbation would be no problem, exchange masturbation would be okay too with the right person.
Blowjobs - giving is not really on my list of things that I'd like to try. Several years ago I would have said not at all. Today it would have to be with a very right person. Receiving a bj from another guy is closely the same criteria; a few years ago not at all interested, today maybe.
Anal - I am definitely open to the idea of receiving, again only from the right person. I'm inexperienced, so that person would have to be considerate of that, and to the point of aborting the attempt if it was causing me pain and not working out well, without having any hard feelings about it. If we are that far along with each other where we are nude and I am trying to take a dick, we are definitely far enough along with each other that I would at least masturbate the guy and/or possibly give that one and only, first bj.
I am actually less interested in “topping” another guy, although if it were a situation where I was with a guy who was topping me, I would certainly be willing to reciprocate for him if he wanted.
Other - I have received enemas and prostate massage from another male on a few occasions, from one guy. So enemas and prostate massage (fingers or toys) are definitely an okay. Again, with the right sort of person and in this case(s) any gender would be okay. I have only given enemas to one person, a female. I would definitely be okay with giving enemas to another guy, provided that I was getting them too.
As another poster had posted, I still have zero interest in kissing/making out with another male.