We always had an OK sex life. Sometimes we do it every day, sometimes 3 weeks between no big deal. Typical for us was get in bed, watch TV, I'd play with her pussy, she'd fondle my dick, kiss for a while, I'd lick her to orgasm, we fuck, fun over. Some nights we'd go again an hour later. There was some days I'd do her in the kitchen, back yard, garage, etc but was always a quickie.
Now....We've been into mfm fun with a guy we know. Took more than several times with him to get comfy but now she goes into full slut mode when he's with us, we fuck her all night and she is into it big time. He always goes 3 times, has gone 4, I do twice then we fuck again after he leaves. She'll clean a dick off after she gets fucked while other guy fucks her. She'll take it in her butt hole. She'll swallow a load. You name it she does it with him and me.
All the next week she is horny as hell, we fuck a LOT but she's not the fuck slut she is when he's with us. During mfm fun she wants fucked a lot. Just her and me it's way more tame.