Let me make it clear now, my DH doesn't expect or even ask me to do this. I am asking this because I have noticed on a couple of relationships threads that some women 'service' their DPs in this way when they don't want sex themselves.
I have a real problem with this concept. Oral sex is as much a sex act as intercourse is to me. If I perform oral on my DH, it is part of a mutually satisfying experience - I do it to him because I am horny and it gives me pleasure to give him pleasure, iyswim. And I will get my just desserts too 
The idea of all these women giving cold bj's to their partners, not for their mutual enjoyment but just to stop him pestering them, fills me with horror tbh.
Is it just me?