How to introduce bdsm into a relationship.?

[Dabox]

Long story short, she is my high school sweet heart, we split up for 8 years cause we both moved away. Came back and we are together again, at the time I didn't have cravings for the bdsm lifestyle. We are both very open people and talk about anything, so I started playing a bit more in bed, like tieing her to the bed etc, she loves it. When I told her to do some researching about bdsm at home she got turned off a bit and won't talk to me about it. I know she will try anything once and same here, but I want to get into more of a kink relationship with her lol.. Just don't know what the next step would be... I don't want to push her into it and I want her to understand it without me seeing so... weird.. Any tips?
Lol not at the time being no, I live in an apartment with a roommate that I went to high school with too... his room is literally next to mine, he will be moving out soon, she usually grabs the pillow and puts it on her face when we mess around lmao.
Well, I know she enjoys some things in bondage... cause sometimes she throws me on my bed and ties me up etc, she did send me a text when she was researching some stuff and said "I am not wearing a dog collar lol" which was kinda cute.. I didn't show her sites we were just texting and I said that I was interested in the whole power exchange etc from bdsm, and that is when she started researching on it by herself. I know she likes handcuffs and some toys.. and she likes it when I spank her too... so I am not sure how far I should push this, she doesn't like to have power over me that much.. once and awhile she will push me over and go my turn etc..