Are you serious? How are these 2 the same people, smh... But yes. Even naturally, without any injections you can get bigger lips tho. Here I'll give you few tips; you can choose and do some of them or do all at them.
1. EXFOLIATE: I use bodyshop lipscuff Its amazing, it exfoliates and moisturize. £8.00 on the website. But of course there are lots of DIYs that you can do it at home. Use brown sugar, honey, coconut oil and voila!
2.MOISTURIZE: There are tons of products and I don't think it really matter which one to use. But vaseline and blistex are good ones.
3.CONTURE: With a natural color lip liner, draw a line just outside of your lips. Like this you can use a nude lipstick or even nothing and still have bigger lips.
4.LIP ENHANCERS: Fullips Lip Enchancers are 20$. Its so much cheaper, easier and faster than injections. You can carry it to anywhere and get bigger lips in few minutes.
BONUS: Every time you brush your teeth, brush your lips as well.