How can I encourage my boyfriend to be more confident and assertive?

Hey, so my boyfriend and I have not been seeing each other for that long of time. He is a very sweet, nice guy who is fun to spend time and I really enjoy being with. The only thing, and I know I still have the issue where my exes that I had a very personal relationship with are still a bit in the back of my mind whom I tend to compare others to. Despite how sweet and considerate my boyfriend is, I wish he was more assertive sexually and able to take the reigns on situations, deciding what we will do and there to defend me in situations. Just really being 'my man' and I'm his 'girl'. He is quite soft spoken and meek, and I would love if he was just a little bit more rowdy and with his actions in everyday life and more personally/sexually.

And ideas how I can help coax him out of his shell?
How can I encourage my boyfriend to be more confident and assertive?
Post Opinion