Finances in a Relationship

So my boyfriend got a new dog. She is adorable. She's about 2 months old and he got her from an adoption shelter. Cupcake has already peed and pooped all over the apartment. It's like she doesn't know that she has to do this outside!!!! Puppy training is NOT easy. She was surprisingly a bit expensive to "adopt" at $450, but my boyfriend purchased her with his poker earnings. (sigh: to the other girls with boyfriends obsessed with poker, have you learned yet??)

Anyway, this leads me to talk finance.

My boyfriend is in finance and I am in the medical field (aka the service field). He has earning potentials through the roof, while I am probably set on a 10-20k salary increase in the next 20 years at this rate (thanks to my most recent .02% raise). My measly earnings do not qualify me to become a potential pet owner. I offered to be Cupcake's mom and foot half of her needs, which is compensated mostly by $$$. This weekend, I blew about 100 bucks on her food, wee-wee pads, lease, etc. etc. I am more than happy to care for Cupcake financially, but, I can barely take care of myself. I feel like an asshole!! I told my bf my concerns and his understanding made me feel a bit better.

Budgeting for a relationship is hard especially if you don't make too much. Budgeting for a boyfriend + puppy is harder! So what are some ways to cut corners and save?

1. Propose $10 dinners with your boyfriend.
My bf and I started this about a week ago and it has been fantastic!! Some of our 10 dollar meals include: garlic Parmesan mashed red potatoes with steamed broccoli and rib-eye steak! The meal was not only cheap, but it was quite delicious! (i'll include images and recipes later). We also recently made chicken lime tacos..which were delicious!!
As we alternate days, we are only spending about 30-40 each a week! This definitely saves us money by not going out as much or even drinking at bars as well.

2. Get into the stock market.
Luckily, I have a little bit of money coming from a super secret savings account(I guess not so secret anymore). With this, I plan on opening from Scottrade accounts. Basically, they are like E-trade, but it is cheaper to trade.

With the help of my finance whiz BF, I plan on taking about 2-5k and flipping that into more.

3. Change your source of entertainment.
Recently, my bf and I have been renting out DVDs instead of going out and doing more expensive type activities. We also love having friends over and hosting $5 buy in poker nights. It's fun and it's a lot cheaper than buying a beer at an LA bar for 8 bucks and buying so-so appetizers for $15 a plate. Those days are long gone for me.

Well, those are my 3 tips of the day. And I am currently working on improving my results by following through with this. What are some other ways that you can save with your bf/spouse or alone?