Feeling Torn

No fancy full detailed story here sorry but I F30 married a man40 recently and afterwards his daughter violet who's 20 moved in with us.
She spent time getting to know me after the wedding as her mum kicked her out and we got on really well.
My husband recently went away for work and I was surprised when on the second night violet walked in naked and got into bed with me. She said it's nicer than sleeping alone.
Then we had sex infact we had lots of sex and this happened every night he was gone and I feel guilty but she's so beautiful I can't stop and want to carry on.
Thats my confession and I don't know what to do.