My hotwife has asked me to suck her lover

My wife has always been a hotwife. I have enjoyed sharing her in mfm, ffm and mfmf fun but in addition she has a couple of other lovers she meets alone. I have also got a FWB. We are happy with this situation and have been married over 10 years. Recently she has brought her two lovers to our home (not at same time), not when i have been here. She has now asked if i would join them, not to fuck but just to watch and to suck her lovers hard. This is a change and would be the first time i'd not be participating. If feels it is moving from a hotwife situation to a cuck situation. I am 100% straight ,never touched another guy's cock in my life.
If you are comfortable with sucking other mens cock,,, try it... It will make a new experience for you
 
The reason she wants you to suck their cocks is so that there is no doubt in your mind that you are sub to them. Th sloppy seconds is to reinforce to you that she belongs sexually to the other guy, lol