There may be something going on behind the scenes; consider that the senior colleague may have been asked by your manager to mentor you and make sure you stay o

There may be something going on behind the scenes; consider that the senior colleague may have been asked by your manager to mentor you and make sure you stay on track or may have been told that they need to show "leadership" before they can get promoted to team lead. Either way, focus on establishing your relationship with your manager. The manager assigns you tasks, not the senior colleague. If you disagree with your colleagues input, follow up with the manager to make sure your approach is correct. Also, see if other colleagues are having similar problems (if your team is larger). If you are correct, you will probably find everybody on the team is simply ignoring them.