Just lately, she seems to have 'taken a shine to him' in a different manner, and has kissed him several times as they've been watching tv and once when she went into his room to wake him up. Thing is, he's not exactly stopped her immediately either..
I've told him time and time again that it's wrong (isn't it?!) and that he wouldn't live much longer if his brother found out, but he still won't stop seeing her. I've told him to distant himself from her etc etc.
Any more advice or thoughts? I need something to make him see sense!!