Go for it Okarin! GO!
Damn this was a good episode and it’s finally getting very interesting. It appears that SERN finally becomes aware of Okarin. There is one thing that worries me, tho. According to ANN there will be 12 episodes, which means that there will be either a shitload of development in the next two episodes (possibly to a point where it gets really bad because too many things happen at once) or there will be a huge cliffhanger. Both would really suck and I vote for a second season.

…a very important part of female anatomy, which happens to be of great interest to males but must not be fondled without consent, which you are currently doing

Is this some kind of new fanservice? Ruka is disarmed and promtly raped by Okarin? Who knows what would’ve happened if those two were alone…
Back to the episode itself: It was epic! Urushibara Ruka is now delicious cake instead of delicious trap, but she still has delicious flat chest, which is delicious… Okarin inspects Ruka thoroughly but has to face Kurisu’s wrath as a result. Do I smell envy? Kurisu has a lot more to offer to inspect, but I guess he couldn’t think of a good excuse to fondle her, so he went for Ruka. His harem lab gets more and more girls. Even Suzuha became a member of the harem lab.

Hmm… strict tsundere tensai hentai 2ch shoujo… it’s getting better and better. Every time you think you’ve seen it all, god slaps you in the face with this
In any case, Suzuha gets extra screentime this episode. She tells Okarin that she is trying to meet her father, Barrel Titor (?), the next day. If she misses that, she’ll have to leave the town (why?!). Okarin tells Suszuha to come to his lab for one last time whether she meets her dad or not, but she never shows up and sends Okarin a mail saying “I’m sorry, goodbye” instead. To stop her from leaving, Okarin sends himself a D-Mail to follow Suzuha, regardless of what Kurisu says. The world line moves, and Suzuha stays with them (seriously, just what happens?).
Okarin also got a mail earlier stating “I am watching you” followed by a picture of pudding, which likely refers to the gel-phenomenon occuring during physical time travel (Gel-Banana, Jellyman’s Report). If this assumtion is true – and that’s what makes the episode so interesting – SERN has caught wind of Okarin’s experiments.
Anime, Steins;Gate