Husband/dad looking for advice

I'm a 47 year old husband and dad, my marriage and family life is very happy but my wife recently confessed to giving our son oral. It's only been oral and started on Halloween. She says it's been going on almost everyday. Sex outside our marriage is not new to us. We've been to a few house parties and have played together and separate many times.

I guess I'm just here because the family twist is very new to me! I'd like to get some input from others in this situation, other parents or their adult children. I'm OK with the sex I'm just not sure where this can go? The baggage it can create?

Thanks!