Triplets against Eighth notes timing

[nowinterweather]

Hey... I'm new to the forums so I hope this is in the right place.

Anyway, I started working on Chopin's Nocturne No.20 in C#minor. It's the first time I've ever really had to play triplets against eighth notes, and it hasn't been too hard, but I am curious about the timing. For reference, I'm mainly talking about bars 15, 21, and 22.

When I play the triplets in the right hand against the eighth notes in the left hand, I wind up playing both hands together, then playing the second right hand note, followed by the second left hand note, and finishing on the last right hand note. Essentially, I'm playing RL-R-L-R (RL being right and left together). However, I've seen people play it RL-R-RL (as in right and left together, then the middle note of the triplet, then finishing on both together. I can play it both ways, but I would like to know which is correct. Thanks in advance.

Also, if I did a horrible job explaining this, then let me know and I'll try again.

[nystul]

The second straight eighth note should be halfway between the second triplet eighth and the third triplet eighth.