The Word says that we are not to "share in other people's sins" 1 Tim. 5:22   and that we are to do all in our power to avoid even the "appearance of evil." 1Thess 5:22.

The Bible unequivocally condemns this kind of behaviour and you have a perfect   right to insist that you will not allow it under your roof.

One word of caution. The Christian parent who makes this kind of decision  must take care to share it in the Spirit of Christ. A harsh, condemnatory, hostile or arrogant attitude will not help those we wish to influence to respect our convictions.

"Let your speech at all times be gracious (pleasant and winsome), seasoned (as it were) with salt, (so that you may never be at a loss) to know how you ought to answer anyone (who puts a question to you)." Col. 4:6 Amplified.