It may be too soon for you in your and Rane and Draco's relationship to be confortable with sleepovers. (I assume he is asking that Rane stay at his place overnight.) Please be able to talk to Rane and Draco about this - you have the right to tell them that, even if the resolution does not turn out to be exactly what you want.
Is there some middle ground you would be confortable with? Also, try to narrow down what you are uncomfortable with. Is it the waking up together? (Since Beloved and I are in a LDR, we have not had to confront this yet - it would likely bother me too to have her wake up in another's bed - and vice versa.) Is it the time away from you and your home? Is it that you are specifically excluded? If you can narrow down the 2 or 3 things that really tweak you about this situation, sometimes that helps in finding resolutions. For example, if her waking up elsewhere in the morning is the main driver (and I'm not saying it is), perhaps they could have an afternoon nap together but return home for evening.
Finally, don't take all the responsibility for the ending/continuing of their relationship on your shoulders! You are not responsible for that. Yes, you have influence as a partner but that is ultimately between them. Do not take on burdens that are not (solely) your own.