Learn Russian: Нам обидно заставлять студентов читать это. - It hurts us to force the students to read this.

Just like жаль (a pity) or лень (too lazy), обидно is used here as an impersonal state category. The person experiencing the emotion takes the Dative case (нам), and the action that causes this feeling is expressed with an infinitive (заставлять).

Why is обидно translated as "it hurts" instead of "it is offensive"?

While обидно comes from обида (offense/insult), in everyday Russian it frequently expresses a feeling of being hurt, upset, or disappointed about a situation. Нам обидно captures the emotional pain or regret of having to force the students.

There are two infinitives in a row here (заставлять and читать). Who is doing which action?

Russian allows stacking infinitives when one verb controls another. The logical subject of заставлять (to force) is нам. The direct object of that forcing is студентов, which then acts as the logical subject for the next infinitive, читать (the students do the reading).

Why use the imperfective заставлять rather than the perfective заставить?