My (28f) boyfriend (29m) just asked me if I would want my partner to step aside if I could live forever.

My boyfriend (29m) and I (28f) have been together for 7 years and are thinking about getting married. For the last few years I've noticed he always says things that make the conversation turn in the direction of if I were given the chance to live forever, would I want him to step aside and let me do it? It started as a random thing and now it's been coming up more frequently. This happened again this weekend.<br><br>He will bring up a random topic, and then somehow turn the topic into a debate about if I were given the chance to live forever, would I want him to step aside so I could live forever?<br><br>For example, we had a conversation over dinner about something related to NASA. Then somehow that turned into a debate about if I were given the chance to live forever, would I want him to step aside so I could live forever?<br><br>Another time we were watching a movie with Tom Hanks. My boyfriend made a comment about Tom Hanks and then somehow that turned into a debate about if I were given the chance to live forever, would I want him to step aside so I could live forever?<br><br>I keep telling him no, that's not something I am interested in. But he keeps pushing the issue. He will joke about it sometimes, but also sometimes he seems really serious. He will ask me "but do you know how much money that would cost? I couldn't let you do that." I'm not sure what the cost would be, but it's not a real thing, so I don't know why he brings it up.<br><br>I feel like he's insecure about us getting older and dying. But he keeps pushing this topic on me. And it's getting annoying.<br><br>Should I be concerned?