During the act of fellatio, the girl allows semen to enter her mouth and proceeds to pass it on to her partner's mouth. He then spits it, now lukewarm, into the girl's vagina in hopes of impregnating her. If successful, this act is called Lovelling.
Stefan: yo i'm so lonely and i want my girl to have a baby, but i'm scared of sex..
Ian: i would suggest you lovelling that bitch!