How can I attach a curtain to my blinds/place curtains without drilling the walls? Aiming for 100% coverage, likely to buy blackout drapes.

Considered tension rods but I don't have the depth in my window frame with the (horizontal) blinds. Would remove the blinds but curtains aren't supposed to be visible and my window directly faces the front office :/.

I know I could just drill and spackle/paint but my roomate's never rented before and is paranoid about breaking the lease terms. Also I'd need to buy a drill.

> pic related ;_;

Literally a bedsheet, push pins and paper clips.