Yes, you can taste the cock.
I've enjoyed doing this since our 1st mfmf swing. Just something about tasting another's cock on your wife.
During one mfm with a friend, they were in a 69, her on top. I leaned in for a kiss, she pulled away from his cock, we kissed. Fresh cock taste and breath. After the kiss, before she could go back to sucking his cock, i just went down on it. This was a bit significant because she is/was disapproving of male bi, and I didn't know how she would react. I guess she enjoyed it because a minute later we both were sucking his cock together, lol. We've since done and enjoyed it.