It's the homophobic part, obviously, that I'm focussed on and I just can't imagine anyone including that bit gratuitously. Fine, if she felt like calling him a 'dirty old man/creep/perv/paedo' for example... given that he had no business dating a child... but to include the offensive and specifically gay slur is really noticeable to me. Sorry to bang on about this, but if he is gay/bisexual/pansexual/a cross dresser or whatever, ordinarily, who cares, but it's extremely relevant to this investigation, as it could be his reason for needing to shut down anyone who might expose him if it's something he wants or feels he needs to keep secret/private.
I can't spell it out, but I assume we are both talking about the same vile word here? And it is prejudicial. Totally. And it's not just something that comes spilling out in anger (I don't believe) unless one has reason to feel betrayed/angered/lied to on the basis of one's partner's sexuality.