married threesome. no judgement

My husband and I have been married 4 years and have 1 child and 1 on the way. He's had a threesome before in his past and has asked me before if I would ever have one or have sex with another girl and let him watch. Lately I've been considering a threesome with another girl and only him penetrating me while I please her. Anyone ever been in that situation before and what was the outcome!? 😈😈