twofiveseven257 said:
Is there a tag like no genitals visible or obscured penetration for things like these? Could also tie in with ambiguous_penetration sometimes, but these are both male/male.

ambiguous_penetration refers to the part being penetrated being ambiguous, not the gender of either character. I believe you may have confused this with either ambiguous_penetrating or ambiguous_penetrated.

ambiguous_penetration should be fine for both of them.