I started at 29, 7 years in to a relationship with partner that has always been sexless from day one due to issues on her part that I won't disclose on here. Back then the idea that I'd ever 'crack' and punt/have an affair etc. would've filled me with total horror but I guess time takes its toll.
And yes mumsnetters, I'm aware that seeing WGs anonymously rather than ending a long term, otherwise happy relationship due to a lack of sex that is outside of either my or my partner's control makes me satan incarnate.