For T! Logan, have you watch a firework with him yet? I think "I owe you a beer" is a latest romantic event with him in this current update (0.43) (repeatable event not include)
For Bernard too, if you get his 4th heart so that mean you already watch a firework with him. Which mean romantic event with him is all done for now (repeatable event not include) but we can max out his likes at 100 too. So if you haven't reach 100 likes with him, you should go for that.
For Caleb, after you got his 1st heart, you can get his 2nd heart by picnic with him during daytime (before 17.00). After you finished this picnic event and if you have his 1st heart, you will have a sex scene with him and get his 2nd heart.