You’re right, UITM: Mary shouldn’t have hidden this from you. But she assumed—incorrectly, as it turned out—you would have a problem with those texts. It was a reasonable assumption on her part, since swapping flirty texts with a stranger is regarded as “out of bounds” by most. While this makes Mary’s failure to disclose look a little worse, we live in a culture that defines absolutely everything as cheating—don’t get me started on the idiocy that is “micro-infidelities” and the idiots pushing that toxic concept—and as a consequence, people not only lack perspective (oh, to live in a world where everyone regarded harmless flirtation as no big deal!) but also the language to honestly discuss our need for a little harmless erotic affirmation from someone who isn’t obligated to find us attractive, i.e., not a spouse or partner.
So, yeah, stop answering that drunk girl’s summonses. Let her know you want more than sex, and if she’s not interested in something more, you’re not interested in her. As for those erectile issues, SWAT, try having sex sober, earlier in the evening, and with someone who doesn’t regard your dick as a consolation prize. I bet they clear right up.