Can silicone implants rupture if your partner puts most of his body weight on your chest?

Implants can rupture under any condition of trauma, but what you are presenting is a very unlikely situation to lead to a rupture

can handle the forces you describe but as they age, the shells do get weaker and blunt force trauma to your chest can result in rupture.  When you push the implant around, you should feel the shell as its moved.  If you cannot appreciate the shell, then a ruptures should be suspect and you should get checked.

A good quality implant can easily resist all the weight of a person.But after some years the implant can experience changes and then have rupture.So you can have your sexual intercourse according you and your partner preferences with not concerning about the implants. If an implant experience rupture during a sexual relation it is because it was going to be ruptured any case and need to be replaced.

All implants will fail at some point but the scenario you mention is not likely to cause a rupture. Over time implant shells can develop a weak area and a small hole can develop. Modern silicone implants are not liquid and therefore do not leak or change size or shape if they get a hole so knowing if a hole has developed can be difficult. If you ever are worried be sure and visit your surgeon.