"Satisfying the older sister's desires with good reason" Kissing...licking breasts...the older sister's desires gradually becoming excessive! HUNTB-480

I'm really troubled lately because my sister got dumped by her boyfriend. She's always been a lonely person, and now she's taking it out on me. She asks for kisses and hugs, which makes me feel incredibly awkward. Even worse, she'll put her hands inside me or lick my genitals! Sometimes she'll even make taboo requests like "just one thrust!" Although I refuse, my penis is already so erect that penetration is unavoidable. Now I'm like a woman in a brothel, fully accommodating my sister's sexual needs.