sex at home is dull now and its making me resent the lifestyle

this is going to sound ungrateful. weve been in the LS about 3 yrs (cape town, mid 40s) and overall its been great for our marriage we communicate more we laugh more etc etc. BUT. sex at home has become... fine. just fine. and i dont know if its because we put all our peak energy into play nights or if its just normal long term marriage stuff and i was kidding myself that the LS would fix that part. when we play with others its electric. when its just us its loving and warm and kinda boring. and im starting to resent the lifestyle for spoiling the contrast?? has anyone hit this and figured a way back to home stuff being exciting again