Go for it. Make sure they're 18 like was previous mentioned. Just be ready for one of them to fall in love with you. 18 year old girls going straight to college are unpredictable and likely to change over time. Feed them enough, water every day, and you should be okay.
Are you even looking for something long term? Be sure you're clear about intentions with them from the get go if you want to prevent future HUGE issues.
And if you want to prevent issues like you used to have about sexual relations, then I would recommend making sure that's not all they're after. You're not a peace of meat!