People actually do this???

I am actually sick and disgusted at what my partner told me about one of his work mates today and want to see if this is actually a thing or these people are just as horrific as I think.. So apparently while breast feeding their son this couple has had sex at the same time, like his behind her while she’s on her side and the baby is feeding in front of her.. I am far from a prude but my god that actually makes me sick 🤢 my partner wanted all of us to hang out sometime but after hearing that I really don’t want to meet these people.. is it just me or is that twisted?