You keep licking at her pussy and occasionally look up at her and notice that her eyes are closed. In a way, you want her to look at you with Bob's cock in her mouth but you can't make out if she is refusing to make eye contact with you or just enjoying sucking another man's cock while she is being eaten out at the same time.
Strangely, you are so incredibly aroused and want to kiss your wife so badly right now while she is sucking Bob's cock. Lisa has hold of your hair so firmly though, that you couldn't move even if you wanted to....